In an unprecedented discovery, paleontologists working in China have found the fossilized remains of an ancient bird with ornamented tooth enamel. Called Sulcavis geeorum, the bird lived during the Early Cretaceous period, about 121 to 125 million years ago. And as its fine row of robust teeth indicate, it likely had a highly specialized diet much different than the beaked birds of today.

Sulcavis was an enantiornithine, an early group of birds that lived in large numbers during the dinosaur era. But unlike other birds, this new fossilized specimen features a discrete set of teeth with grooves on the inside surface, which probably strengthened them against harder food items. The bird likely used these teeth not to grind or chew, but to crush tough objects.

According to the researchers, a team led by Jingmai O'Connor, no previous bird species have any form of dental ornamentation, whether it be preserved ridges, striations, or serrated edges. It was during the Mesozoic era that other birds were losing their teeth (which they inherited from their dinosaur ancestors). O'Connor's team is not sure why Sulcavis was so successful during the Cretaceous, only to die out. They speculate that differences in diet must have played a part, and that the teeth were not a good long-term adaptation.

The study, which was published in the Journal of Vertebrate Paleontology, suggests that the teeth allowed Sulcavis to adopt a durophagous diet — a diet consisting of prey that had hard exoskeletons, including insects and crabs.

The finding greatly increases the known diversity of tooth shape in early birds, suggesting a wider array of ecological diversity among birds than previously assumed.